ES2733936T3 - Video decoding procedure based on hierarchical encoded block pattern information - Google Patents

Abstract

A video decoding method, the method comprising: extracting, from a sequence of bits, encoded image data of a current snapshot assigned to a maximum encoding unit of the current snapshot; extracting, from the sequence of bits, information about a coded depth for the maximum coding unit in which the information about the coded depth comprises division information of a current coding unit, the maximum coding unit is hierarchically divided into coding units of at least one depth according to the division information which is a flag indicating whether the current coding unit of a current depth, between the coding units, is divided into coding units of a lower depth; when the division information of the current coding unit indicates that the current coding unit of the current depth is no longer divided as the current coding unit of the encoded depth, extracting, from the sequence of bits, information about a mode of prediction of the current coding unit indicating an intra mode or an inter mode, information about a type of partition indicating a size of a prediction unit included in the current coding unit and information about a unit size of transforming the current coding unit, determining at least one prediction unit obtained from the current coding unit using information about a type of partition and determining at least one transformation unit obtained from the current coding unit using the information about a size of a transformation unit; perform intra prediction or inter prediction in the current coding unit based on the at least one prediction unit using information about a prediction mode; extract, from the sequence of bits, coding unit pattern information indicating whether texture information of the current coding unit has been encoded; according to whether the coding unit pattern information indicates that the texture information of the current coding unit has been encoded, extracting, from the bit sequence, transformation unit pattern information indicating whether information has been encoded of texture of a transformation unit of the at least one transformation unit; according to whether the transformation unit pattern information indicates that the texture information of the transformation unit has been encoded, perform an inverse transformation in the transformation unit; and decode the encoded image data for the maximum coding unit based on the prediction unit and the transformation unit included in the current coding unit, in which the maximum coding unit has a square shape with a width and height in powers of 2, wherein the transformation unit pattern information of a luminance component transformation unit indicates whether texture information of the luminance component transformation unit has been encoded; and wherein the transformation unit pattern information of a chromatic component transformation unit indicates whether texture information of the chromatic component transformation unit has been encoded.

Description

DESCRIPTION

Video decoding procedure based on hierarchical encoded block pattern information

Technical field

Exemplary embodiments relate to video decoding.

Prior art

As hardware is being developed and supplied to reproduce and store high-resolution or high-quality video content, a need for a video codec to efficiently encode or decode high-resolution or high-quality video content increases. In a video codec of the related art, the video is encoded according to a limited encoding procedure based on a macroblock having a predetermined size. Also, in the video codec of the related art, block pattern information encoded in macro block units is encoded. Video coding procedures are disclosed in KIM J et al. “Enlarging MB size for high fidelity video coding beyond HD”, 36. VCEG MEETING; 8-10-2008 - 10

10-2008 SAN DIEGO, United States; (VIDEO CODINGEXPERTS GROUP OF ITU-T SG.16) (20081005), No.

VCEG-AJ21, ISSN 0000-0086, XP030003643. Video decoding procedures are also disclosed in QUALCOMM INC, "Video Coding Using Extended Block Sizes Q6 / 16", ITU-T SG16 MEETING; 01-21-2009 - 6-2

2009; GENEVA ,, (20090119), No. T09-SG16-C-0123, ISSN 0000-0057, XP030003764.

Divulgation

Technical problem

The apparatus and procedures consistent with the disclosure provide video coding and decoding using information indicating whether texture information of a coding unit has been encoded and in consideration of a hierarchical depth.

Technical solution

In accordance with one aspect of an exemplary embodiment, a video decoding method according to claim 1 is provided herein. The procedure includes: receiving and analyzing a bit sequence of encoded video, extracting, from the sequence of bits, the encoded image data of a current image assigned to a maximum coding unit of the current image, information about the encoded depth of the maximum coding unit, information about an encoding mode, and coding unit pattern information indicating whether the texture information of the maximum coding unit has been encoded; and decoding the encoded image data for the maximum encoding unit, based on information about the encoded depth of the maximum encoding unit, information about the encoding mode, and the encoding unit pattern information.

Advantageous effects

The coding unit pattern information is used based on a hierarchically structured coding unit and transformation unit. Therefore, the encoding unit pattern information can be encoded in an encoding unit that is larger than a macroblock or has a variable size data unit. Also, the coding unit pattern information can be encoded in an encoding unit, which includes a plurality of hierarchically structured transformation units according to a tree structure, in an integrated manner. Accordingly, the coding / decoding and transmission efficiency of the coding unit pattern information can be improved.

Description of the drawings

The foregoing and / or other aspects will become more evident by the detailed description of their disclosure with reference to the attached drawings in which:

bloques de

aparato de codificación de vídeo;Figure 1 is a diagram

blocks of

video coding apparatus;

bloques de

aparato de decodificación de vídeo;Figure 2 is a diagram

blocks of

video decoding apparatus;

Figure 3 is a diagram to describe a concept of coding units;

bloques de un codificador de imagen basado en unidades de codificac La Figura 5 es un diagrama de bloques de un decodificador de imagen basado en unidades de codificación;Figure 4 is a diagram

blocks of an image encoder based on encoding units Figure 5 is a block diagram of an image decoder based on encoding units;

Figure 6 is a diagram illustrating deeper coding units according to depths, and partitions;

Figure 7 is a diagram to describe a relationship between a coding unit and transformation units;

Figure 8 is a diagram for describing encoding information of encoding units corresponding to an encoded depth;

Figure 9 is a diagram of deeper coding units according to the depths; Figures 10 to 12 are diagrams to describe a relationship between coding units, prediction units and transformation units;

Figure 13 is a diagram for describing a relationship between a coding unit, a prediction unit or a partition, and a transformation unit, according to coding mode information. Figure 14 is a flow chart illustrating a procedure. encoding a video;

Figure 15 is a flow chart illustrating a video decoding procedure;

Figure 16 is a block diagram of a video coding apparatus that uses coding unit pattern information;

Figure 17 is a block diagram of a video decoding apparatus that uses coding unit pattern information;

Figures 18 to 20 are block diagrams illustrating coding unit pattern information corresponding to a coded depth when a coding unit corresponding to a coded depth includes a transformation unit;

Figures 21 to 23 illustrate coding unit pattern information corresponding to an encoded depth when an encoding unit corresponding to the encoded depth includes four transformation units;

Figures 24 to 26 illustrate coding unit pattern information corresponding to an encoded depth when an encoding unit corresponding to the encoded depth includes a plurality of transformation units;

Figure 27 is a diagram illustrating hierarchical coding unit pattern information;

Figure 28 is a flow chart illustrating a video coding procedure using encoding unit pattern information; Y

Figure 29 is a flowchart illustrating a video decoding process using encoding unit pattern information, in accordance with an exemplary embodiment.

Better mode

In accordance with the present invention, a method is provided as set forth in the appended claims. Other features of the invention will become apparent from the dependent claims, and the description that follows. In accordance with one aspect of an exemplary embodiment, a video decoding method is provided, according to claim 1 herein.

According to an example: a video decoding procedure includes: receiving and analyzing a bit sequence of encoded video; extracting, from the sequence of bits, encoded image data of a current snapshot assigned to a maximum encoding unit of the current snapshot, information regarding an encoded depth of the maximum encoding unit, information regarding an encoding mode , and coding unit pattern information indicating whether texture information of the maximum coding unit has been encoded; and decoding the encoded image data for the maximum encoding unit, based on the information regarding the encoded depth of the maximum encoding unit, the information regarding the encoding mode, and the coding unit pattern information.

The coding unit can be characterized by a maximum size and depth.

The depth can indicate a number of times a coding unit is hierarchically divided, and as the depth becomes deeper, the deeper coding units according to the depths can be divided from the maximum coding unit to obtain units of coding. minimum coding

The depth can be made deep from a greater depth to a lower depth.

As the depth deepens, the number of times the coding unit is divided maximum can increase, and a total number of possible times that the maximum coding unit is divided can correspond to a maximum depth.

The maximum size and maximum depth of the coding unit can be predetermined.

The coding unit pattern information with respect to the maximum coding unit may include at least one of the coding unit pattern information corresponding to encoded depth, which is set for a coding unit corresponding to the encoded depth, and hierarchical coding unit pattern information according to transformation depths, which indicates whether hierarchical coding unit pattern information has been encoded with respect to a lower depth.

If the encoding unit pattern information with respect to the encoding units according to the encoded depths indicates that the texture information of the maximum encoding units has been encoded, decoding of the encoded image data may include extracting information of the transformation unit pattern indicating whether texture information of at least one transformation unit included in the coding unit corresponding to the encoded depth has been encoded.

If the transformation unit pattern information indicates that the texture information of the transformation unit has been encoded, decoding of the encoded image data may include decoding the encoded texture information.

If the transformation unit pattern information indicates that the texture information of the transformation unit has not been encoded, decoding of the encoded image data may include decoding the transformation unit using information regarding transformation units adjacent to The transformation unit.

The coding unit pattern information corresponding to coded depth can be extracted according to color components of the image data.

If the coding unit corresponding to the encoded depth includes at least four transformation units, the first group can be divided into four lower groups, and the predetermined bit coding unit pattern information corresponding to the encoded depth can be extracted additionally for each of the four lower groups.

According to an example, a video encoding procedure includes: dividing a current snapshot of the video into a maximum encoding unit; determine a coded depth to emit a final coding result according to at least one division region, which is obtained by dividing a region of the maximum coding unit according to the depths, encoding the at least one division region, based on a depth that becomes deep in proportion to a number of times the region of the maximum coding unit is divided; and issue image data that is the result of final coding according to the at least one division region, and encode and issue information about the encoded depth and a prediction mode and a unit coding unit pattern information maximum encoding, in which the coding unit pattern information indicates whether texture information of the maximum coding unit has been encoded.

The emission of the image data may include establishing and encoding the coding unit pattern information, based on whether all the transformation coefficients of the texture information of the maximum coding unit are 0.

The emission of the image data may include establishing and encoding the encoding unit pattern information corresponding to the encoded depth, according to the encoded depth of the maximum encoding unit, based on whether all the unit transformation coefficients of coding that corresponds to the coded depths are 0.

If hierarchical coding unit pattern information and texture information are not encoded with respect to a coding unit corresponding to a greater depth than a current depth, then the emission of the image data may include establishing and encoding pattern information. of unit of hierarchical coding from a depth more superior to the current depth.

The method may further include determining if at least one of the coding unit pattern information corresponding to coded depth and the hierarchical coding unit pattern information for each of the at least one transformation depth, is to be used. with respect to at least one of the current snapshot, a cut and the maximum coding unit.

The issuance of the coding unit pattern information may include determining whether the transformation unit pattern information is to be set for a transformation unit included in a coding unit corresponding to the encoded depth, based on pattern information. of coding unit with respect to the maximum coding unit, in which the unit pattern information of transformation indicates whether texture information of the transformation unit has been encoded.

According to an example, an apparatus for decoding video includes: a receiver that receives and analyzes a sequence of encoded video bits; a subtractor that extracts, from the bit sequence, encoded image data of a current snapshot assigned to a maximum encoding unit, information regarding an encoded depth of the maximum encoding unit, information regarding an encoding mode, and coding unit pattern information indicating whether texture information of the maximum coding unit has been encoded; and an image data decoder that decodes the encoded image data in the maximum encoding unit, based on the information regarding the encoded depth of the maximum encoding unit, the information regarding the encoding mode, and the information of coding unit pattern.

According to an example, a video coding apparatus includes: a maximum coding unit splitter that divides a current snapshot into a maximum coding unit; a coding unit determiner that determines a coded depth to emit a final coding result according to at least one division region, which is obtained by dividing a region of each of the maximum coding unit according to the depths, coding the at least one division region, based on a depth that becomes deep in proportion to a number of times the region of the maximum coding unit is divided; and an output unit that emits image data that is the result of final encoding according to the at least one division region, and that encodes and outputs information about the encoded depth and a mode of encoding and unit pattern information coding of the maximum coding unit, wherein the coding unit pattern information indicates whether texture information of each of the at least one maximum coding unit has been encoded.

According to an example, a computer-readable recording medium has a computer program recorded therein to execute the previous video decoding procedure.

According to an example, a video decoding procedure includes: extracting, from a sequence of encoded video bits, encoded image data of a current snapshot assigned to a maximum encoding unit of the current snapshot, information regarding an encoded depth of the maximum coding unit, and coding unit pattern information indicating whether texture information of the maximum coding unit has been encoded; and decoding the encoded image data for the maximum coding unit, based on the information extracted with respect to the encoded depth of the maximum coding unit, and the coding unit pattern information.

Mode for the invention

Hereinafter, a procedure and apparatus for video coding and a procedure and apparatus for video decoding will be described in accordance with the disclosure with reference to the accompanying drawings. In particular, video encoding and decoding performed based on encoding units according to a tree structure that includes spatially independent hierarchical data units according to the disclosure will be described with reference to Figures 1 to 15. Also, it will be described in detail the encoding and decoding of video performed using coding unit pattern information with respect to an encoding unit according to such a tree structure in accordance with the disclosure with reference to Figures 16 to 29. Here. Descriptive memory, it is understood that expressions such as "at least one of", when preceding a list of elements, modify the entire list of elements, and do not modify the individual elements of the list.

In the present specification, an encoding unit is an encoding data unit in which the image data is encoded on one encoder side and an encoded data unit in which the encoded image data is decoded on one side. of decoder, according to the disclosure. Also, an encoded depth indicates a depth where an encoding unit is encoded.

In the present specification, an 'image' may indicate a still image for a video or a moving image, ie the same video.

A method and apparatus for video coding and a method and apparatus for video decoding, in accordance with the disclosure will be described with reference to Figures 1 to 15.

Figure 1 is a block diagram of a video coding apparatus 100 in accordance with the disclosure. Referring to Figure 1, the video encoding apparatus 100 includes a maximum encoder unit divisor 110, an encoder unit determinator 120 and an output unit 130.

The maximum encoding unit divisor 110 may divide a current snapshot based on a maximum encoding unit for the current snapshot of an image. If the current snapshot is larger than the maximum encoding unit, the image data of the current snapshot can be divided into at least one maximum encoding unit. The maximum coding unit according to the disclosure may be a data unit having a size of 32x32, 64x64, 128x128, 256x256, etc., in which one form of the data unit is a square having a width and height in squares of 2. The image data can be output to the encoder unit determinator 120 according to the at least one maximum coding unit.

An encoding unit according to the disclosure can be characterized by a maximum size and depth. The depth indicates a number of times the coding unit is spatially divided from the maximum coding unit. Therefore, as the depth deepens, deeper coding units can be divided according to the depths from the maximum coding unit to a minimum coding unit. A maximum coding unit depth is a higher depth and a minimum coding unit depth is a lower depth. Since a size of a coding unit corresponding to each depth is reduced as the depth of the maximum coding unit is reduced, a coding unit corresponding to a greater depth may include a plurality of corresponding coding units at lower depths.

As described above, the image data of the current snapshot is divided into one or more maximum encoding units according to a maximum encoding unit size, and each of the maximum encoding units may include encoding units. deeper that divide according to the depths. Since the maximum coding unit according to an exemplary embodiment is divided according to the depths, the image data of a spatial domain included in the maximum coding unit can be classified hierarchically according to the depths.

A maximum depth and maximum size of a coding unit, which limit the total number of times a height and width of the maximum coding unit is hierarchically divided, can be predetermined. The encoder unit determinator 120 encodes at least one division region obtained by dividing a region of the maximum coding unit according to the depths, and determines a depth to emit finally encoded image data according to the at least one region of division. For example, the encoder unit determinator 120 determines an encoded depth by encoding the image data in the deepest encoding units according to the depths, according to the maximum encoding unit of the current snapshot, and selecting a depth that It has minimal coding errors. Therefore, the encoded image data of the encoding unit corresponding to the determined encoded depth is output by the encoder unit 120. Also, the coding units corresponding to the encoded depth can be considered as encoded coding units.

The determined encoded depth and the encoded image data according to the determined encoded depth are output to the output unit 130.

The image data in the maximum coding unit is encoded based on the deepest coding units corresponding to at least one depth equal to or below the maximum depth, and the results of the coding of the image data are compared based in each of the deepest coding units. A depth having the minimum coding errors can be selected after comparing coding errors of the deeper coding units. At least one coded depth can be selected for each maximum coding unit.

The size of the maximum coding unit is divided as one coding unit is divided hierarchically according to the depths, and as the number of coding units increases. Also, even if the coding units correspond to the same depth in a maximum coding unit, it is determined whether to divide each of the coding units corresponding to the same depth at a lower depth by measuring an encoding error of the data of image of each coding unit, separately. Therefore, even when the image data is included in a maximum coding unit, the image data is divided into regions according to the depths and the coding errors may differ according to the regions in the one maximum coding unit. . Therefore, the coded depths may differ according to the regions in the image data. Therefore, one or more encoded depths can be determined in a maximum coding unit, and the image data of the maximum coding unit can be divided according to coding units of at least one encoded depth.

Accordingly, the coding unit determinator 120 can determine coding units having a tree structure included in the maximum coding unit. The coding units having a tree structure according to an exemplary embodiment include coding units that correspond to a given depth to be the encoded depth, of all the deepest coding units included in the maximum coding unit. A coding unit of an encoded depth can be determined hierarchically according to the depths in the same region of the maximum coding unit, and can be determined independently in different regions. Similarly, a coded depth in a current region can be determined independently from a coded depth in another region.

A maximum depth according to the disclosure is an index related to a number of times of division from a maximum coding unit to a minimum coding unit. A first maximum depth according to the disclosure may indicate a total number of times of division from the maximum coding unit to the minimum coding unit. A second maximum depth according to the disclosure may indicate a total number of depth levels from the maximum coding unit to the minimum coding unit. For example, when a depth of the maximum coding unit is 0, a depth of a coding unit, in which the maximum coding unit is divided once, can be set to 1, and a depth of a coding unit, in which the maximum coding unit is divided twice, it can be set to 2. At this point, if the minimum coding unit is a coding unit in which the maximum coding unit is divided four times, there are 5 levels of depth of depths 0, 1, 2, 3 and 4. In this case, the first maximum depth can be set to 4, and the second maximum depth can be set to 5.

The prediction and transformation coding can be performed according to the maximum coding unit. Prediction coding and transformation can also be performed based on the deepest coding units according to a depth equal to, or depths less than, the maximum depth, according to the maximum coding unit. The transformation can be performed according to an orthogonal transformation procedure or integer transformation.

Since the number of deeper coding units increases each time the maximum coding unit is divided according to the depths, including coding by prediction coding and transformation can be performed on all the deeper coding units generated as The depth becomes deeper. For convenience of description, prediction coding and transformation will now be described based on a coding unit of a current depth, a maximum coding unit.

The video coding apparatus 100 may vary a size or shape of a data unit to encode the image data. To encode image data, operations are performed, such as prediction coding, transformation, and entropy coding, and at this time, the same data unit can be used for all operations or different data units can be used for each operation. . For example, the video encoding apparatus 100 may select not only an encoding unit to encode the image data, but also a different data unit from the encoding unit to perform prediction coding in the image data in the coding unit

To perform the coding by prediction in the maximum coding unit, the coding by prediction can be performed based on a coding unit that corresponds to an encoded depth, that is, based on a coding unit that is no longer divided into units of coding corresponding to a lower depth. Hereinafter, the coding unit that is no longer divided and becomes a base unit for prediction coding will be referred to as a prediction unit. A partition obtained by dividing the prediction unit may include a prediction unit or a data unit obtained by dividing at least one of a height and width of the prediction unit.

For example, when a coding unit of 2Nx2N (where N is a positive integer) is no longer divided and a prediction unit of 2Nx2N is made, a partition size can be 2Nx2N, 2NxN, Nx2N or NxN. Examples of a type of partition include symmetric partitions that are obtained by symmetrically dividing a height or width of the prediction unit, partitions obtained by asymmetrically dividing the height or width of the prediction unit (such as 1: non: 1), partitions which are obtained by dividing the prediction unit geometrically, and partitions that have arbitrary forms.

A prediction mode of the prediction unit may be at least one of an intra mode, an inter mode and a jump mode. For example, intra mode or inter mode can be performed in the partition of 2Nx2N, 2NxN, Nx2N, or NxN. Also, the jump mode can only be performed on the 2Nx2N partition. The coding is done independently in a prediction unit in a coding unit, thus selecting a prediction mode that has a minimum coding error.

The video coding apparatus 100 can also perform the transformation in the image data into an encoding unit based not only on the encoding unit for encoding the image data, but also based on a data unit that is different from the coding unit

To perform the transformation in the coding unit, the transformation can be performed based on a data unit that is smaller than or equal to the coding unit. For example, the data unit for transformation may include a data unit for an intra mode and a data unit for an inter mode.

A unit of data used as a basis for the transformation will be referred to as a unit of transformation. A transformation depth indicating a number of times of division to reach the transformation unit by dividing a height and width of the coding unit can be established also in the transformation unit. For example, in a current coding unit of 2Nx2N, a transformation depth can be 0 when a size of a transformation unit is also 2Nx2N, it can be 1 when each of the height and width of the current coding unit is Divide into two equal parts, fully divided into 4A1 transformation units, and the size of the transformation unit is therefore NxN, and can be 2 when each of the height and width of the current coding unit is divided into four equal parts, totally divided into 4A2 transformation units, and the size of the transformation unit is therefore N / 2xN / 2. For example, the transformation unit can be established according to a hierarchical tree structure, in which a transformation unit of a higher transformation depth is divided into four transformation units of a lower transformation depth according to hierarchical characteristics of A depth of transformation.

Similar to the coding unit, the transformation unit in the coding unit can be recursively divided into regions with smaller size, so that the transformation unit can be independently determined in units of regions. Therefore, the residual data in the coding unit can be divided according to the transformation of the tree structure according to the transformation depths.

The coding information according to coding units corresponding to an encoded depth uses not only information about the encoded depth, but also information about information related to coding and prediction transformation. Therefore, the encoder unit 120 determines not It only determines a coded depth that has a minimum coding error, but also determines a type of partition in a prediction unit, a prediction mode according to prediction units, and a size of a transformation unit for transformation.

The coding units according to a tree structure in a maximum coding unit and a method of determining a partition, according to the disclosure; they will be described in detail later with reference to Figures 3 to 12.

The coding unit determinator 120 can measure a coding error of deeper coding units according to the depths using rate-distortion optimization based on Lagrange multipliers.

The output unit 130 outputs the image data of the maximum coding unit, which is encoded based on the at least one encoded depth determined by the encoder unit 120, and information about the encoding mode according to the depth encoded, in a sequence of bits. The encoded image data can be obtained by encoding residual data of an image. The information about the encoding mode according to encoded depth may include at least one of information about the encoded depth, information about the type of partition in the prediction unit, the prediction mode, and the size of the transformation unit .

Information about the coded depth can be defined using division information according to the depths, which indicates whether the coding is done in coding units of a lower depth instead of a current depth. If the current depth of the current coding unit is the encoded depth, image data is encoded and output in the current coding unit, and therefore the division information can be defined that does not divide the current coding unit to a depth lower. Alternatively, if the current depth of the current coding unit is not the encoded depth, the coding is performed in the lower depth coding unit. Therefore, the division information can be defined to divide the current coding unit to obtain the lower depth coding units.

If the current depth is not the coded depth, the coding is done in the coding unit that is divided into the lower depth coding unit. Since there is at least one lower depth coding unit in a current depth coding unit, the coding is performed repetitively in each lower depth coding unit. Therefore, coding can be performed recursively for coding units that have the same depth.

Since the coding units having a tree structure are determined for a maximum coding unit, and information about at least one coding mode is determined for a coding unit of an encoded depth, information about at least a coding mode for a maximum coding unit. Also, an encoded depth of the image data of the maximum coding unit may be different according to the locations since the image data is divided hierarchically according to the depths. Therefore, information about the encoded depth and the coding mode for the image data can be established.

Accordingly, the output unit 130 can assign encoding information about a corresponding encoded depth and an encoding mode for at least one of the encoding unit, the prediction unit, and a minimum unit included in the maximum coding unit .

The minimum unit according to the disclosure may be a regular unit of data obtained by dividing by 4 the minimum coding unit that has the lowest depth. Alternatively, the minimum unit can be a maximum rectangular data unit that can be included in all coding units, prediction units, partition units and transformation units included in the maximum coding unit.

For example, the encoding information emitted through the output unit 130 can be classified into encoding information according to encoding units, and encoding information according to prediction units. The coding information according to the coding units may include at least one of information about the prediction mode and information about a partition size. The coding information according to the prediction units may include at least one of information about an estimated address of an inter mode, information about a reference image index of the inter mode, information about a motion vector, information about a chrominance component of an intra mode, and information about an interpolation procedure of the intra mode. Also, information about a maximum encoding unit size defined according to snapshots, cuts or snapshot groups (GOP), and information about a maximum depth can be inserted into a set of sequence parameters (SPS) or a header of a sequence of bits.

In the video coding apparatus 100, the deepest coding unit may be an encoding unit obtained by dividing by two at least one of a height and a width of an encoding unit of a greater depth, which is one layer per over. In other words, when the size of the current depth coding unit is 2Nx2N, the size of the lower depth coding unit may be NxN. Also, the current depth coding unit having the size of 2Nx2N may include 4 of the lower depth coding units.

Accordingly, the video encoding apparatus 100 can form the encoding units having the tree structure by determining encoding units that have an optimal shape and optimum size for each maximum encoding unit, based on the size of the unit of encoding. Maximum coding and maximum depth determined considering characteristics of the current snapshot. Also, since coding can be performed on each maximum coding unit using any of various prediction modes and transformations, an optimal coding mode can be determined considering characteristics of the coding unit of various image sizes.

Therefore, if an image having a high resolution or a large amount of data is encoded in a macroblock of the related art, a number of macroblocks per snapshot increases excessively. Consequently, a number of pieces of compressed information generated for each macroblock increases, and therefore it can be difficult to transmit the compressed information and the data compression efficiency is reduced. However, using the video coding apparatus 100 according to an exemplary embodiment, the image compression efficiency can be increased since an encoding unit is adjusted while considering characteristics of an image while increasing a maximum unit size. encoding while considering an image size.

Figure 2 is a block diagram of a video decoding apparatus 200, in accordance with the disclosure. Referring to Figure 2, the video decoding apparatus 200 includes a receiver 210, an image data and encoder information subtractor 220, and an image data decoder 230. The definitions of various terms, such as a coding unit, a depth, a prediction unit, a transformation unit, and information about various coding modes, for various operations of the video decoding apparatus 200 are the same or similar. to those described above with reference to Figure 1 and the video coding apparatus 100.

Receiver 210 receives and analyzes a sequence of bits of an encoded video. The image data and encoding information extractor 220 extracts encoded image data for each encoding unit from the analyzed bit sequence, in which the encoding units have a tree structure according to each maximum encoding unit, and issues the extracted image data to the image data decoder 230. The image data extractor 220 and encoding information can extract information about a maximum size of an encoding unit of a current snapshot from a header corresponding to the current snapshot or an SPS.

Also, the image data and encoding information extractor 220 extracts information about an encoded depth and an encoding mode for the encoding units having a tree structure according to each maximum encoding unit, from the bit sequence analyzed. The information extracted about the encoded depth and the encoding mode is output to the image data decoder 230. Therefore, the image data in a sequence of bits is divided into the maximum encoding unit so that the image data decoder 230 decodes the image data for each maximum encoding unit.

Information about the encoded depth and the coding mode according to the maximum coding unit can be set for information about at least one coding unit corresponding to the encoded depth. Additionally, information about the coding mode can include at least one of information about a partition type of a corresponding coding unit that corresponds to the encoded depth, information about a prediction mode, and a size of a transformation unit. Also, the division information according to the depths can be extracted as the information about the coded depth.

The information about the encoded depth and the encoding mode according to each maximum encoding unit extracted by the image data extractor 220 and encoding information is information about an encoded depth and a particular encoding mode to generate an error. minimum coding when an encoder, such as video encoding apparatus 100, repeatedly performs encoding for each deeper coding unit according to the depths according to each maximum coding unit. Accordingly, the video decoding apparatus 200 can restore an image by decoding the image data according to an encoded depth and an encoding mode that generates the minimum encoding error.

Since the coding information about the encoded depth and the coding mode can be assigned to a predetermined data unit of between a corresponding coding unit, a prediction unit and a minimum unit, the image and information data extractor 220 Encoding can extract information about the encoded depth and encoding mode according to the default data units. The predetermined data units to which the same information about the encoded depth and the encoding mode are assigned can be inferred to be the data units included in the same maximum coding unit.

The image data decoder 230 restores the current snapshot by decoding the image data in each maximum encoding unit based on the information about the encoded depth and the encoding mode according to the maximum encoding units. In other words, the image data decoder 230 can decode the encoded image data based on the information extracted about the partition type, the prediction mode, and the transformation unit for each encoding unit between the encoding units which have the tree structure included in each maximum coding unit. A decoding procedure may include at least one of a prediction that includes intra prediction and motion compensation, and an inverse transformation. The inverse transformation can be performed according to the inverse orthogonal transformation procedure or inverse integer transformation.

The image data decoder 230 can perform intra prediction or motion compensation according to a partition and a prediction mode of each encoding unit, based on information about the partition type and prediction mode of the prediction unit. of the coding unit according to coded depths.

Also, the image data decoder 230 can perform reverse transformation according to each transformation unit in the coding unit, based on information about the size of the transformation unit of the coding unit according to encoded depths, to perform the inverse transformation according to maximum coding units.

The image data decoder 230 may determine at least one coded depth of a current maximum coding unit using division information according to the depths. If the division information indicates that the image data is no longer divided into the current depth, the current depth is an encoded depth. Accordingly, the image data decoder 230 can decode encoded data of at least one encoding unit that corresponds to each encoded depth in the current maximum encoding unit using information about the partition type of the prediction unit, the mode prediction, and the size of the transformation unit for each coding unit that corresponds to the encoded depth, and output the image data of the current maximum coding unit.

In other words, the data units that include the coding information that includes the same division information can be collected by observing the established coding information assigned for the predetermined data unit between the coding unit, the prediction unit and the unit minimum In addition, the data units collected can be considered to be a data unit to be decoded by the image data decoder 230 in the same encoding mode.

The video decoding apparatus 200 can obtain information about at least one encoding unit that generates the minimum encoding error when the encoding is performed recursively for each maximum encoding unit, and can use the information to decode the current snapshot. In other words, the coding units having the determined tree structure can be decoded to be the optimal coding units in each maximum coding unit. Also, a maximum size of the coding unit can be determined considering the resolution and an amount of image data.

Therefore, even if the image data has a high resolution and a large amount of data, the image data can be decoded and restored efficiently using a size of an encoding unit and an encoding mode, which is determined adaptively by according to data characteristics of image, using information about an optimal coding mode received from an encoder.

A method of determining coding units having a tree structure, a prediction unit, and a transformation unit, according to the disclosure will now be described with reference to Figures 3 to 13.

Figure 3 is a diagram to describe a concept of coding units according to the disclosure. A size of a coding unit may be expressed in width x height, and may be 64x64, 32x32, 16x16 and 8x8, although it is understood that another exemplary embodiment is not limited thereto. A 64x64 coding unit can be divided into 64x64, 64x32, 32x64 or 32x32 partitions, a 32x32 coding unit can be divided into 32x32, 32x16, 16x32 or 16x16 partitions, a 16x16 coding unit can be divided into 16x16 partitions , 16x8, 8x16 or 8x8, and an 8x8 encoding unit can be divided into 8x8, 8x4, 4x8 or 4x4 partitions.

Referring to Figure 3, the first video data 310 has a resolution that is 1920x1080, a maximum size of a coding unit of 64, and a maximum depth of 2. The second video data 320 has a resolution of 1920x1080, a maximum size of a coding unit of 64, and a maximum depth of 3. The third video data 330 have a resolution of 352x288, a maximum size of a coding unit of 16, and a maximum depth of 1. The depth Maximum shown in Figure 3 indicates a total number of divisions from a maximum coding unit to a minimum decoding unit.

If a resolution is high or a large amount of data, a maximum size of an encoding unit can be large not only to increase the encoding efficiency but also to accurately reflect characteristics of an image. Accordingly, the maximum size of the encoding units of the first and second video data 310 and 320 having a higher resolution than the third video data 330 may be 64.

Since the maximum depth of the first video data 310 is 2, the encoding units 315 of the first video data 310 may include a maximum encoding unit having a long axis size of 64, and encoding units having Long shaft sizes of 32 and 16 since the depths are made deep into two layers by dividing the maximum coding unit twice. Meanwhile, since the maximum depth of the third video data 330 is 1, the encoding units 335 of the third video data 330 may include a maximum encoding unit having a long axis size of 16, and units of coding that have a long axis size of 8 since the depths are made deep to a layer by dividing the maximum coding unit once.

Since the maximum depth of the second video data 320 is 3, the encoding units 325 of the second video data 320 may include a maximum encoding unit having a long axis size of 64, and encoding units having Long shaft sizes of 32, 16 and 8 since the depths are made deep to 3 layers by dividing the maximum coding unit three times. As a depth becomes deep (that is, it increases), detailed information can be accurately expressed.

Figure 4 is a block diagram of an image encoder 400 based on encoding units, in accordance with the disclosure. Referring to Figure 4, the image encoder 400 performs operations of the encoder unit determinator 120 of the video encoding apparatus 100 to encode image data. For example, an intra predictor 410 performs intra prediction in coding units in an intra mode, between a current frame 405, and a motion estimator 420 and a motion compensator 425 performs inter estimation and motion compensation, respectively, in units of coding in an inter mode between the current frame 405 using the current frame 405, and a reference frame 495.

The data emitted from the intra predictor 410, the motion estimator 420, and the motion compensator 425 are output as a quantized transformation coefficient through a transformer 430 and a quantizer 440. The quantized transformation coefficient is restored as data in a spatial domain through a reverse quantizer 460 and a reverse transformer 470. The data restored in the spatial domain is output as reference frame 495 after post-processing through an unlocking unit 480 and a loop filtration unit 490. The quantized transformation coefficient can be output as a sequence of bits 455 through an entropy 450 encoder.

For the image encoder 400 to be applied in the video coding apparatus 100, the elements of the image encoder 400, that is, the intra predictor 410, the motion estimator 420, the motion compensator 425, the transformer 430, the quantifier 440, the entropy encoder 450, the reverse quantizer 460, the reverse transformer 470, the unlocking unit 480, and the loop filtering unit 490, perform operations based on each encoding unit between encoding units having a tree structure while considering the maximum depth of each maximum coding unit.

Specifically, the intra predictor 410, the motion estimator 420, and the motion compensator 425 determine partitions and a prediction mode of each coding unit among the units of coding that have a tree structure while considering a maximum size and a maximum depth of a current maximum coding unit, and the transformer 430 determines a size of the transformation unit in each coding unit from among the coding units that have A tree structure

Figure 5 is a block diagram of an image decoder 500 based on encoding units, in accordance with the disclosure. Referring to Figure 5, an analyzer 510 analyzes encoded image data to be decoded and information about encoding used to decode from a sequence of bits 505. The encoded image data is output as inverse quantized data through a decoder 520 by entropy and an inverse quantizer 530, and the inverse quantized data is restored to image data in a spatial domain through a reverse 540 transformer.

An intra predictor 550 performs intra prediction in encoding units in an intra mode with respect to image data in the spatial domain, and a motion compensator 560 performs motion compensation in encoding units in an inter mode using a frame 585 of reference.

The spatial domain image data, which is passed through the intra predictor 550 and the motion compensator 560, can be output as a frame 595 restored after post-processing through an unlock unit 570 and a unit 580 of loop filtering. Also, the image data that is post processed through the unlocking unit 570 and the loop filtering unit 580 can be output as the reference frame 585.

To decode the image data in the image data decoder 230 of the video decoding apparatus 200, the image decoder 500 can perform operations that are performed after the analyzer 510. In order for the image decoder 500 to be applied in the apparatus Video decoding 200, the elements of the image decoder 500, that is, the analyzer 510, the entropy decoder 520, the reverse quantizer 530, the reverse transformer 540, the intra predictor 550, the motion compensator 560, the unit Unlock 570, and loop filter unit 580, perform operations based on coding units that have a tree structure for each maximum coding unit.

Specifically, intra prediction 550 and motion compensator 560 perform operations based on partitions and a prediction mode for each of the encoding units having a tree structure, and the reverse transformer 540 performs operations based on a size of one transformation unit for each coding unit.

Figure 6 is a diagram illustrating deeper coding units according to depths, and partitions, according to the disclosure. A video coding apparatus 100 according to the disclosure and a video decoding apparatus 200 according to the disclosure use hierarchical coding units to consider features of an image. A maximum height, a maximum width and a maximum depth of coding units can be determined adaptively according to the characteristics of the image, or they can be set differently by a user. The sizes of deeper coding units according to the depths can be determined according to a predetermined maximum size of the coding unit.

Referring to Figure 6, in a hierarchical structure 600 of coding units, according to the disclosure, the maximum height and maximum width of the coding units are each 64, and the maximum depth is 4. Since a depth becomes deep (that is, it increases) along a vertical axis of the hierarchical structure 600, each one is divided by a height and a width of the deepest coding units. Also, a prediction unit and partitions, which are the basis for prediction coding of each deeper coding unit, are shown along a horizontal axis of the hierarchical structure 600.

For example, a first coding unit 610 is a maximum coding unit in the hierarchical structure 600, in which a depth thereof is 0 and a size, that is, a height by width, thereof is 64x64. The depth is deepened along the vertical axis so that the hierarchical structure 600 includes a second coding unit 620 having a size of 32x32 and a depth of 1, a third coding unit 630 having a size of 16x16 and a depth of 2, a fourth coding unit 640 having a size of 8x8 and a depth of 3, and a fifth coding unit 650 having a size of 4x4 and a depth of 4. The fifth coding unit 650 having The size of 4x4 and the depth of 4 is a minimum coding unit.

The prediction unit and the partitions of the coding units 610, 620, 630, 640 and 650 are arranged along the horizontal axis according to each depth. In other words, if the first coding unit 610 having the size of 64x64 and the depth of 0 is a prediction unit, the prediction unit can be divided into partitions included in the first coding unit 610, that is a 610 partition which has a size of 64x64, 612 partitions that have a size of 64x32, 614 partitions that have a size of 32x64, or 616 partitions that have a size of 32x32.

Similarly, a prediction unit of the second encoding unit 620 having the size of 32x32 and the depth of 1 can be divided into partitions included in the second encoding unit 620, that is a partition 620 having a size of 32x32 , 622 partitions that are 32x16 in size, 624 partitions that are 16x32, and 626 partitions that are 16x16 in size.

Similarly, a prediction unit of the third coding unit 630 having the size of 16x16 and the depth of 2 can be divided into partitions included in the third coding unit 630, i.e. a partition having a size of 16x16 included in the third coding unit 630, partitions 632 having a size of 16x8, partitions 634 having a size of 8x16, and partitions 636 having a size of 8x8. Similarly, a prediction unit of the fourth coding unit 640 having the size of 8x8 and the depth of 3 can be divided into partitions included in the fourth coding unit 640, that is a partition having a size of 8x8 included in the fourth coding unit 640, partitions 642 having a size of 8x4, partitions 644 having a size of 4x8, and partitions 646 having a size of 4x4.

The fifth coding unit 650 having the size of 4x4 and the depth of 4 is the minimum coding unit and a lower depth coding unit. A prediction unit of the fifth coding unit 650 is assigned to a partition having a size of 4x4.

To determine the at least one encoded depth of the encoding units of the maximum encoding unit 610, the encoder unit determinator 120 of the video encoding apparatus 100 performs encoding for encoding units corresponding to each depth included in the unit 610 maximum coding.

A number of deeper coding units according to the depths that include data in the same range and the same size increases as the depth deepens. For example, four coding units that correspond to a depth of 2 are required to cover data that is included in a coding unit that corresponds to a depth of 1. Therefore, to compare coding results of the same data according to the depths, each of the coding unit corresponding to the depth of 1 and four coding units corresponding to the depth of 2 is coded.

To perform the coding for a current depth between the depths, a minimum coding error for the current depth can be selected by coding for each prediction unit in the coding units corresponding to the current depth, along the horizontal axis of 600 hierarchical structure. Alternatively, the minimum coding error can be searched by comparing the minimum coding errors according to the depths, coding for each depth as the depth deepens along the vertical axis of the hierarchical structure 600. A depth and a partition that have the minimum coding error in the first encoding unit 610 can be selected as the encoded depth and a partition type of the first encoding unit 610.

Figure 7 is a diagram to describe a relationship between a coding unit 710 and transformation units 720, in accordance with the disclosure. A video coding apparatus 100 in accordance with the disclosure and a video decoding apparatus 200 in accordance with the disclosure encode and decode, respectively, an image in accordance with encoding units having sizes smaller than or equal to an encoding unit maximum for each unit of maximum coding. Transformation unit sizes can be selected for transformation during encoding based on data units that are not larger than a corresponding coding unit.

Referring to Figure 7, for example, in the video encoding apparatus 100, if a size of the encoding unit 710 is 64x64, the transformation can be performed using the transformation units 720 having a size of 32x32.

Also, the data of the coding unit 710 having the size of 64x64 can be encoded by performing the transformation in each of the transformation units having the size of 32x32, 16x16, 8x8 and 4x4, which are smaller than 64x64, and then A transformation unit that has the minimum coding errors can be selected.

Figure 8 is a diagram for describing coding information of coding units corresponding to a coded depth, in accordance with the disclosure. Referring to Figure 8, the output unit 130 of a video encoding apparatus 100 according to the disclosure may encode and transmit first information 800 about a type of partition, second information 810 about a prediction mode, and third information 820 about a size of a transformation unit for each coding unit that corresponds to a coded depth, such as information about a coding mode.

The first information 800 indicates information about a form of a partition obtained by dividing a prediction unit from a current coding unit, in which the partition is a data unit for prediction coding the current coding unit. For example, a current coding unit CU_0 that has a 2Nx2N size can be divided into any one of an 802 partition that has a size of 2Nx2N, an 804 partition that has a size of 2NxN, an 806 partition that has a size of Nx2N, and an 808 partition that has a size of NxN. At this point, the first information 800 about a partition type is set to indicate one of partition 804 that has a size of 2NxN, partition 806 that has a size of Nx2N, and partition 808 that has a size of NxN .

The second information 810 indicates a prediction mode of each partition. For example, the second information 810 may indicate a prediction coding mode performed on a partition indicated by the first information 800, that is, an intra mode 812, an inter mode 814 or a jump mode 816.

The third information 820 indicates a transformation unit to be based on when the transformation is performed in a current coding unit. For example, the transformation unit may be a first intra-transformation unit 822, a second intra-transformation unit 824, a first inter-transformation unit 826, or a second inter-transformation unit 828.

A subtractor 220 of image data and encoding information of a video decoding apparatus 200 in accordance with the disclosure may extract and use the information 800, 810 and 820 to decode, according to each deeper coding unit.

Figure 9 is a diagram of deeper coding units according to the depths, according to the disclosure. The division information can be used to indicate a change in depth. The division information indicates whether a coding unit of a current depth is divided into coding units of a lower depth.

Referring to Figure 9, a prediction unit 910 for prediction coding of an encoding unit 900 having a depth of 0 and a size of 2N_0x2N_0 may include partitions of a partition type 912 having a size of 2N_0x2N_0, a partition type 914 that has a size of 2N_0xN_0, a partition type 916 that has a size of N_0x2N_0, and a partition type 918 that has a size of N_0xN_0. Figure 9 only illustrates the partition types 912 to 918 that are obtained by symmetrically dividing the prediction unit 910, but it is understood that one type of partition is not limited thereto in another exemplary embodiment. For example, partitions of the prediction unit 910 may include asymmetric partitions, partitions that have a predetermined shape, and partitions that have a geometric shape.

Prediction coding is done repetitively on a partition that is 2N_0x2N_0, two partitions that are 2N_0xN_0, two partitions that are N_0x2N_0, and four partitions that are N_0xN_0, according to Each type of partition. The coding by prediction in an intra mode and an inter mode can be performed on partitions that have the sizes of 2N_0x2N_0, N_0x2N_0, 2N_0xN_0, and N_0xN_0. Prediction coding in a jump mode is performed only on the partition that is 2N_0x2N_0.

Coding errors that include prediction coding in partition types 912 to 918 are compared, and the minimum coding error between partition types is determined. If an encoding error is the smallest in one of the partition types 912 to 916, the prediction unit 910 may not be divided into a lower depth.

If the coding error is the smallest in partition type 918, a depth of 0 to 1 is changed to divide partition type 918 in operation 920, and coding is performed repeatedly in coding units 930 that they have a depth of 2 and a size of N_0xN_0 to look for a minimum coding error.

A prediction unit 940 for prediction coding of the coding unit 930 having a depth of 1 and a size of 2N_1x2N_1 (= N_0xN_0) may include partitions of a partition type 942 having a size of 2N_1x2N_1, a type 944 of partition that has a size of 2N_1xN_1, a type 946 of partition that has a size of N_1x2N_1, and a type 948 of partition that has a size of N_1xN_1.

If an encoding error is the smallest in partition type 948, a depth is changed from 1 to 2 to divide partition type 948 in operation 950, and coding is performed repeatedly in coding units 960, which have a depth of 2 and a size of N_2xN_2 to search for a minimum coding error.

When a maximum depth is d, the division operations according to each depth can be performed even when a depth is made d-1, and the division information can be coded until when a depth is one from 0 to d-2. For example, when coding is performed until when the depth is d-1 after an encoding unit corresponding to a depth of d-2 is divided into step 970, a prediction unit 990 for prediction coding of a 980 encoding unit that has a depth of d-1 and a size of 2N_ (d-1) x2N_ (d-1) can include partitions of a type 992 partition that has a size of 2N_ (d-1) x2N_ ( d-1), a type 994 partition that has a size of 2N_ (d-1) xN_ (d-1), a type 996 partition that has a size of N_ (d-1) x2N_ (d-1) , and a type 998 partition that has a size of N_ (d-1) xN_ (d i).

Prediction coding can be performed repetitively on a partition that has a size of 2N_ (d-1) x2N_ (d-1), two partitions that have a size of 2N_ (d-1) xN_ (d-1), two partitions that have a size of N_ (d-1) x2N_ (d-1), four partitions that have a size of N_ (d-1) xN_ (d-1) of partition types 992 to 998 to search a type of partition that has a minimum coding error.

Even when partition type 998 has the minimum coding error, since a maximum depth is d, a CU_ (d-1) coding unit that has a depth of d-1 is no longer divided to a lower depth, and An encoded depth for the coding units of a current maximum coding unit 900 is determined to be d-1 and a partition type of the current maximum coding unit 900 can be determined to be N_ (d-1) xN_ ( d-1). Also, since the maximum depth is d and a minimum coding unit 980 having a lower depth of d-1 is no longer divided to a lower depth, no division information is established for the minimum coding unit 980.

A data unit 999 can be considered a minimum unit for the current maximum coding unit. A minimum unit according to the disclosure may be a rectangular data unit obtained by dividing a minimum coding unit 980 by 4. By repetitively coding, a video encoding apparatus 100 according to the disclosure can select a depth that has the minimum coding error by comparing encoding errors according to the depths of the encoding unit 900 to determine an encoded depth , and establish a corresponding partition type and prediction mode as a coding depth coding mode.

As such, the minimum coding errors according to the depths are compared at all depths of 1 d, and a depth having the minimum coding errors can be determined as a coded depth. At least one of the encoded depth, the type of partition of the prediction unit, and the prediction mode can be encoded and transmitted as information about an encoding mode. Also, since a coding unit is divided from a depth of 0 to a coded depth, only division information of coded depth is set to 0, and depth division information excluding coded depth is set to 1.

A subtractor 220 of image data and encoding information of a video decoding apparatus 200 according to the disclosure may extract and use the information about the encoded depth and the prediction unit of the encoding unit 900 to decode the partition 912. The video decoding apparatus 200 may determine a depth, at which the division information is 0, as a coded depth using division information according to the depths, and use information about a coding mode of the corresponding depth to decode.

Figures 10 to 12 are diagrams to describe a relationship between coding units 1010, prediction units 1060 and transformation units 1070, according to the disclosure.

Referring to Figures 10 to 12, the encoding units 1010 are encoding units having a tree structure, corresponding to encoded depths determined by a video encoding apparatus 100 in accordance with the disclosure, in an encoding unit maximum The prediction units 1060 are partitions of prediction units of each of the coding units 1010, and the transformation units 1070 are transformation units of each of the coding units 1010.

When a depth of a maximum coding unit is 0 in coding units 1010, the depths of coding units 1012 and 1054 are 1, the depths of units 1014, 1016, 1018, 1028, 1050 and 1052 are 2, the depths of units 1020, 1022, 1024, 1026, 1030, 1032 and 1048 of coding are 3, and the depths of units 1040, 1042, 1044 and 1046 of coding are 4.

In the prediction units 1060, some units 1014, 1016, 1022, 1032, 1048, 1050, 1052 and 1054 encoding are obtained by dividing the coding units of the coding units 1010. For example, partition types in encoding units 1014, 1022, 1050 and 1054 have a size of 2NxN, partition types in encoding units 1016, 1048 and 1052 have a size of Nx2N, and a partition type of the coding unit 1032 has a size of NxN. The prediction units and the partitions of the coding units 1010 are less than or equal to each coding unit.

The reverse transformation or transformation is performed on image data of the coding unit 1052 in the transformation units 1070 into a data unit that is smaller than the coding unit 1052. Also, the units 1014, 1016, 1022, 1032, 1048, 1050 and 1052 of coding in the transformation units 1070 are different from those in the prediction units 1060 in terms of sizes and shapes. For example, the video encoding and decoding apparatus 100 and 200 according to the disclosure can perform intra prediction, motion estimation, motion compensation, transformation and inverse transformation individually in a data unit in the same coding unit.

Accordingly, the coding is performed recursively in each of the coding units having a hierarchical structure in each region of a maximum coding unit to determine an optimal coding unit, and therefore coding units having a recursive tree structure. The coding information may include at least one of division information about an encoding unit, information about a type of partition, information about a prediction mode, and information about a size of a transformation unit. Table 1 shows exemplary encoding information that can be set by video encoding and decoding devices 100 and 200.

Table 1

An output unit 130 of the video encoding apparatus 100 may issue the encoding information about the encoding units having a tree structure, and a subtractor 220 of image data and encoding information of the video decoding apparatus 200 You can extract the encoding information about the encoding units that have a tree structure from a received bit sequence. The division information indicates whether a current coding unit is divided into coding units of a lower depth. If the division information of a current depth d is 0, a depth at which a current coding unit is no longer divided into a lower depth is an encoded depth, and therefore information about a partition type can be defined, prediction mode and a size of a unit of transformation for coded depth. If the current coding unit is further divided according to the division information, the coding is performed independently into four division coding units of a lower depth.

A prediction mode can be one of an intra mode, an inter mode and a jump mode. The intra mode and inter mode can be defined in all partition types, and the jump mode can only be defined in a partition type that has a size of 2Nx2N.

Information about the partition type may indicate symmetric partition types that have sizes of 2Nx2N, 2NxN, Nx2N and NxN, which are obtained by symmetrically dividing at least one of a height and width of a prediction unit, and asymmetric partition types which have sizes of 2NxnU, 2NxnD, nLx2N and nRx2N, which are obtained by asymmetrically dividing at least one of the height and width of the prediction unit. The types of asymmetric partition that have the sizes of 2NxnU and 2NxnD can be obtained respectively by dividing the height of the prediction unit into 1: 3 and 3: 1, and the types of asymmetric partition that have the sizes of nLx2N and nRx2N can be obtained respectively dividing the width of the prediction unit into 1: 3 and 3: 1

The size of the transformation unit can be set to be two types in the intra mode and two types in the inter mode. For example, if the division information of the transformation unit is 0, the size of the transformation unit can be 2Nx2N, which is the size of the current coding unit. If the division information of the transformation unit is 1, the transformation units can be obtained by dividing the current coding unit. Also, if a partition type of the current coding unit that has the size of 2Nx2N is a symmetric partition type, a size of a transformation unit can be NxN, and if the partition type of the current coding unit is An asymmetric partition type, the size of the transformation unit can be N / 2xN / 2.

The coding information about coding units having a tree structure may include at least one of a coding unit corresponding to a coded depth, a prediction unit and a minimum unit. The coding unit corresponding to the coded depth may include at least one of a prediction unit and a minimum unit that includes the same coding information.

Accordingly, it is determined whether adjacent data units are included in the same encoding unit that corresponds to the encoded depth by comparing encoding information of the data units. adjacent. Also, a corresponding coding unit corresponding to a coded depth is determined using coding information from a data unit, and therefore a distribution of coded depths in a maximum coding unit can be determined.

Therefore, if a current coding unit is predicted based on coding information from adjacent data units, data unit coding information can be referenced directly into deeper coding units adjacent to the current coding unit.

Alternatively, if a current coding unit is predicted based on coding information of adjacent data units, data units adjacent to the current coding unit are searched using data unit coding information, and reference can be made to the adjacent coding units sought to predict the current coding unit.

Figure 13 is a diagram for describing a relationship between a coding unit, a prediction unit or a partition, and a transformation unit, according to the coding mode information in Table 1 according to the disclosure. Referring to Figure 13, a maximum coding unit 1300 includes units 1302, 1304, 1306, 1312, 1314, 1316, and 1318 encoded depth coding. At this point, since the coding unit 1318 is a coding unit of an encoded depth, the division information can be set to 0. The information about a partition type of the coding unit 1318 having a size of 2Nx2N it can be set to be one of a partition type 1322 that has a size of 2Nx2N, a partition type 1324 that has a size of 2NxN, a partition type 1326 that has a size of Nx2N, a partition type 1328 that has a size of NxN, a partition type 1332 that has a size of 2NxnU, a partition type 1334 that has a size of 2NxnD, a partition type 1336 that has a size of nLx2N, and a partition type 1338 that has a size of nRx2N.

When the partition type is set to be symmetric, that is, partition type 1322, 1324, 1326 or 1328, a transformation unit 1342 is set that has a size of 2Nx2N if the division information (TU size flag ) of a transformation unit is 0, and a transformation unit 1344 is set that has a size of NxN if a TU size flag is 1.

When the partition type is set to be asymmetric, that is, partition type 1332, 1334, 1336 or 1338, a transformation unit 1352 is set that has a size of 2Nx2N if a TU size flag is 0, and a transformation unit 1354 having a size of N / 2xN / 2 is established if a TU size flag is 1.

Referring to Figure 13, the TU size flag is a flag that has a value of 0 or 1, although it is understood that the disclosure is not limited to a 1-bit flag. For example, a transformation unit can be divided hierarchically having a tree structure while the TU size flag increases from 0.

In this case, the size of a transformation unit that has actually been used can be expressed using a TU size flag of a transformation unit, according to the disclosure together with a maximum size and minimum size of the transformation unit. According to the disclosure, a video encoding apparatus 100 may encode maximum transformation unit size information, minimum transformation unit size information, and a maximum TU size flag. The result of encoding the maximum transformation unit size information, the minimum transformation unit size information, and the maximum TU size flag can be inserted into an SPS. According to the disclosure, a video decoding apparatus 200 may decode video using the maximum transformation unit size information, the minimum transformation unit size information, and the maximum TU size flag.

For example, if the size of a current coding unit is 64x64 and a maximum transformation unit size is 32x32, the size of a transformation unit can be 32x32 when a TU size flag is 0, it can be 16x16 when the TU size flag is 1, and it can be 8x8 when the TU size flag is 2.

As another example, if the size of the current coding unit is 32x32 and a minimum transformation unit size is 32x32, the size of the transformation unit can be 32x32 when the TU size flag is 0. At this point, The TU size flag cannot be set to a value other than 0, since the size of the transformation unit cannot be less than 32x32.

As another example, if the size of the current coding unit is 64x64 and a maximum TU size flag is 1, the TU size flag can be 0 or 1. At this point, the TU size flag cannot set to a value other than 0 or 1.

Therefore, if the maximum TU size flag is defined as MaxTransformSizelndex, a minimum transformation unit size is MinTransformSize, and a transformation unit size is RootTuSize when the TU size flag is 0, then a size of current minimum transformation unit CurrMinTuSize which can be determined in a current coding unit, can be defined by Equation (1):

CurrMinTuSize = max (MinTransformSize, RootTuSize / (2AMaxTransformSizeIndex)) ...... (1).

Compared to the current CurrMinTuSize minimum transformation unit size that can be determined in the current coding unit, a RootTuSize transformation unit size when the TU size flag is 0 may indicate a maximum transformation unit size that can be selected in the system. In equation (1), RootTuSize / (2AMaxTransformSizeIndex) indicates a transformation unit size when the RootTuSize transformation unit size, when the TU size flag is 0, is divided a number of times corresponding to the flag of Maximum TU size, and MinTransformSize indicates a minimum transformation size. Therefore, a smaller value between RootTuSize / (2AMaxTransformSizeIndex) and MinTransformSize may be the minimum current CurrMinTuSize transformation unit size that can be determined in the current encoding unit.

According to the disclosure, the maximum transformation unit size RootTuSize may vary according to the type of a prediction mode. For example, if a current prediction mode is an inter mode, then RootTuSize can be determined using Equation (2) below. In equation (2), MaxTransformSize indicates a maximum transformation unit size, and PUSize indicates a current prediction unit size: RootTuSize = min (MaxTransformSize, PUSize) ...... (2).

That is, if the current prediction mode is inter mode, the RootTuSize transformation unit size when the TU size flag is 0 may be a smaller value between the maximum transformation unit size and the unit size of current prediction:

If a prediction mode of a current partition unit is an intra mode, RootTuSize can be determined using Equation (3) below. In equation (3), PartitionSize indicates the size of the current partition unit:

RootTuSize = min (MaxTransformSize, PartitionSize) ...... (3).

That is, if the current prediction mode is intra mode, the RootTuSize transformation unit size when the TU size flag is 0 may be a smaller value between the maximum transformation unit size and the unit size. of current partition.

However, the current maximum transformation unit size RootTuSize that varies according to the type of a prediction mode in a partition unit is only an example, and it is understood that the disclosure is not limited to the same.

Figure 14 is a flow chart illustrating a method of encoding a video, in accordance with the disclosure. Referring to Figure 14, in operation 1210, a current snapshot is divided into at least one maximum coding unit. A maximum depth indicating a total number of possible division times can be predetermined.

In step 1220, a depth coded to emit a final coding result according to at least one division region, which is obtained by dividing a region of each maximum coding unit according to the depths, is determined by encoding the at least one division region, and an encoding unit is determined according to a tree structure.

The maximum coding unit is divided spatially each time the depth becomes deep, and therefore is divided into coding units of a lower depth. Each coding unit can be divided into coding units of another lower depth by spatially dividing independently of adjacent coding units. The coding is performed repeatedly in each coding unit according to the depths.

Also, a transformation unit is determined according to partition types that have a minimum coding error for each deeper coding unit. To determine an encoded depth having the minimum coding error in each maximum coding unit, coding errors in all the deepest coding units can be measured and compared according to the depths. In step 1230, the encoded image data corresponding to the final encoding result according to the encoded depth is output for each maximum encoding unit, with encoding information about the encoded depth and an encoding mode. The information about the coding mode may include at least one of information about an encoded depth or division information, information about a partition type of a prediction unit, a prediction mode, and a size of a transformation unit . The encoding information about the encoding mode can be transmitted to a decoder with the encoded image data.

Figure 15 is a flow chart illustrating a video decoding procedure, in accordance with the divulgation.

Referring to Figure 15, in step 1310, a sequence of bits of an encoded video is received and analyzed.

In operation 1320, the encoded image data of a current snapshot assigned to a maximum encoding unit, and information about an encoded depth and an encoding mode according to maximum encoding units are extracted from the analyzed bit sequence. The coded depth of each maximum coding unit is a depth that has a minimum coding error in each maximum coding unit. When each maximum coding unit is encoded, the image data is encoded based on at least one data unit obtained by hierarchically dividing the maximum coding unit according to the depths.

According to the information about the encoded depth and the coding mode, the maximum coding unit can be divided into coding units having a tree structure. Each of the coding units having the tree structure is determined as a coding unit that corresponds to an encoded depth, and is optimally encoded to emit the minimum coding errors. Accordingly, the encoding and decoding efficiency of an image can be improved by decoding each piece of encoded image data in the encoding units after determining at least one depth encoded according to encoding units.

In operation 1330, the image data of each maximum encoding unit is decoded based on the information about the encoded depth and the encoding mode according to the maximum encoding units. For example, decoded image data can be reproduced by a playback apparatus, stored in a storage medium or transmitted over a network.

Now, the encoding and decoding of video performed using coding unit pattern information with respect to an encoding unit according to a tree structure will be described in detail, with reference to Figures 16 to 29.

Figure 16 is a block diagram of a video coding apparatus 1400 using encoder unit pattern information, in accordance with the disclosure. Referring to Figure 16, the video coding apparatus 1400 includes a maximum encoder unit divider 1410, an encoded unit determinator 1420, and an output unit 1460. The output unit 1460 includes an encoded image data output unit 1430, an encoded information output unit 1440, and an encoded unit pattern information output unit 1450.

The maximum coding unit divisor 1410 and the encoded unit determiner 1420 correspond to the maximum coding unit divisor 110 and the encoded unit determinator 120 included in the video coding apparatus 100 illustrated in Figure 1, respectively. The operations of the encoded image data output unit 1430 and the encoding information output unit 1440 may be the same as or similar to at least some of the output unit 130 operations included in the encoding apparatus 100 of video of Figure 1. A disclosure in which the encoding unit pattern information output unit 1450 encodes encoding unit pattern information will now be described.

In the current exemplary embodiment, the maximum coding unit divisor 1410 divides a current snapshot of an image, based on a maximum coding unit for the current snapshot. The encoder unit determinator 1420 determines at least one encoded depth by encoding image data in encoding units according to the depths in each maximum coding unit and selects a depth having the minimum coding errors. Therefore, the encoder unit determinator 1420 can determine coding units having a tree structure included in each maximum coding unit.

The encoded image data output unit 1430 emits a sequence of bits of the encoded image data according to the encoded depth in each maximum encoding unit. The coding information output unit 1440 encodes and outputs information regarding the encoding modes according to encoded depths in each maximum encoding unit.

The coding unit pattern information output unit 1450 encodes and outputs coding unit pattern information indicating whether texture information has been encoded for each of the maximum coding units. The texture information includes, for example, at least one of a quantification parameter, a transformation coefficient and a transformation index for a unit of data.

If the video coding apparatus 1400 according to the disclosure corresponds to the image encoder 400 of Figure 4, then estimated / compensated motion data is generated from the image data corresponding to a current encoding unit using the intra predictor 410, the motion estimator 420 and the motion compensator 425 of Figure 4. The estimated / compensated motion data is transformed by the transformer 430 and then quantified by the quantizer 440, thereby generating a transformation coefficient of the current coding unit.

The coding unit pattern information with respect to the current coding unit can be set based on whether all the transformation coefficients of the current coding unit are 0. The transformation coefficients of the current coding unit that are set to be encoded according to the coding unit pattern information, they can be input to the encoder 450 by entropy to be output in a sequence of bits.

The coding unit pattern information is used to determine if the encoded texture is to be transmitted when the texture information is not to be encoded in coding units or when the texture information is to be encoded in coding units. For example, if all the transformation coefficients in the coding units are 0, then the coding unit pattern information is set to indicate that the texture information is not to be encoded. However, if any one of the transformation coefficients in the coding unit is not 0, then the coding unit pattern information is set to indicate that the texture information has been encoded.

According to the disclosure, examples of the coding unit pattern information include coding unit pattern information corresponding to an encoded depth, and hierarchical coding unit pattern information.

The coding unit pattern information corresponding to a coded depth is set for coding units corresponding to at least one coded depth in a maximum coding unit, and indicates whether texture information of a coding unit has been encoded that corresponds to a coded depth. For example, the coding unit pattern information corresponding to an encoded depth may indicate if all the transformation coefficients in coding units according to the depths to an encoded depth are 0.

The hierarchical coding unit pattern information is set for at least one transformation depth, respectively. A transformation depth of a maximum transformation unit is a higher transformation depth, and a transformation unit divides as a transformation depth becomes deeper. Also, a transformation unit of a current transformation depth may include four transformation units, the depths of which are less in a layer than the current transformation depth.

Hierarchical coding unit pattern information corresponding to a current transformation depth indicates whether hierarchical coding unit pattern information has been encoded with respect to transformation units of the lower depths of a layer. The coding unit pattern information output unit 1450 establishes and encodes hierarchical coding unit pattern information for each of the transformation depths that vary from a transformation depth greater than a transformation depth lower than a predetermined depth

For example, the hierarchical coding unit pattern information can be set for each of the transformation depths, and the texture information of a transformation unit corresponding to the lowest transformation depth can be encoded.

A transformation depth of a transformation unit can be linked to a coded depth and depth of a corresponding coding unit. For example, a transformation depth can be set to be fixedly equal to or less than a layer than a depth of a coding unit. Otherwise, a transformation depth can be set to be different from a depth of a coding unit.

According to the disclosure, in the video coding apparatus 1400, if only one or both of the coding unit pattern information corresponding to an encoded depth is to be encoded and the hierarchical coding unit pattern information can be selectively set to at least one data unit selected from a GOP, a snapshot, a cut and a maximum coding unit. For example, if both the coding unit pattern information corresponding to an encoded depth and the hierarchical coding unit pattern information are used, then the coding unit pattern information output unit 1450 may establish Hierarchical coding unit pattern for each of depths that vary from a deeper depth to a current coded depth and can establish and encode coding unit pattern information corresponding to a coded depth for a coding unit corresponding to the current coded depth. The coding unit corresponding to the coded depth may include at least one transformation unit. The transformation unit pattern information indicating whether texture information has been encoded can be set for the at least one transformation unit, respectively. For example, the transformation unit pattern information indicates whether a current transformation unit includes a transformation coefficient other than 0.

When the texture information of transformation units is to be decoded, the output unit 1450 of encoding unit pattern information may establish transformation unit pattern information for each of the transformation units, and may establish and encode coding unit pattern information corresponding to an encoded depth of an encoding unit that includes The transformation units.

If all the transformation coefficients in the encoded depth coding unit are not 0, then the encoded image data output unit 1430 may not emit encoded texture information. If all transformation units belonging to an encoding unit corresponding to the encoded depth do not include transformation coefficients other than 0, then the output unit 1450 of encoding unit pattern information does not encode the unit pattern information of transformation for the coding unit that corresponds to the coded depth. Instead, the coding unit pattern information output unit 1450 may establish and encode coding unit pattern information corresponding to an encoded depth, which indicates that the texture information of the coding unit corresponding to the encoded depth must not be encoded, for the coding unit corresponding to the encoded depth.

The coding unit pattern information corresponding to the encoded depth can be set according to color components of the image data. For example, the coding unit pattern information corresponding to the encoded depth can be set for both of a luminance component and a chrominance component, or it can be set for each of the luminance component, the chrominance component, a first chrominance component, and a second chrominance component (see Figures 18 to 26 for a more detailed description).

The coding unit pattern information to which one or more bits are assigned can be set to one of coding units according to the depths and transformation units for each of the maximum coding units.

Figure 17 is a block diagram of a video decoding apparatus 1500 using encoder unit pattern information, in accordance with the disclosure. Referring to Figure 17, the video decoding apparatus 1500 includes a receiver 1501, a subtractor 1505, and an image data decoder 1540. The extractor 1505 includes an image data obtaining unit 1510, an encoding information extractor 1520, and an encoding unit pattern information extractor 1530.

The receiver 1501 and the image data decoder 1540 correspond to the receiver 210 and the image data decoder 230 included in the video decoding apparatus 200 of Figure 2, respectively. The operations of the image data obtaining unit 1510, the encoding information extractor 1520, and the image data decoder 1540 are the same as or similar to at least some of the operations of the image data extractor 220 and encoding information of the video decoding apparatus 200 of Figure 2. A method of performing decoding using encoder unit pattern information extracted by the encoder unit pattern information extractor 1530 will now be described with reference to Figure 17.

Receiver 1501 receives and analyzes a bit sequence of encoded video. Extractor 1505 extracts various types of encoding information from the result of analyzing the bit sequence. The image data obtaining unit 1510 can obtain image data that has been encoded in units of maximum coding units, from the result of analyzing the bit sequence. The encoder information extractor 1520 analyzes the bit sequence and then extracts information regarding an encoded depth and an encoding mode for each of the maximum encoding units, from a current snapshot header.

The encoder unit pattern information extractor 1530 extracts coding unit pattern information indicating whether texture information of a maximum coding unit has been encoded, for each of the maximum coding units. The encoder unit pattern information extractor 1530 can extract coding unit pattern information corresponding to an encoded depth and hierarchical coding unit pattern information with respect to a current maximum coding unit, such as pattern information of coding unit.

If only one or both of the coding unit pattern information corresponding to a coded depth is to be extracted and the hierarchical coding unit pattern information can be set in units of a GOP, a snapshot, a cut, or a maximum coding unit.

For example, an encoding unit pattern information unit corresponding to an encoded depth may be extracted with respect to an encoding unit according to an encoded depth, or a hierarchical coding unit pattern information unit may be extracted with with respect to each of the depths that vary from a depth greater than the coded depth. A unit of the coding unit pattern information may be predetermined bits. For each of the maximum coding units, one or more bits of coding unit pattern information may be set to any of coding units according to the depths or a transformation unit. For example, if the coding unit pattern information is in the form of flags, then a unit of the coding unit pattern information may be one bit.

The image data decoder 1540 reconstructs the current snapshot by decoding the image data that has been encoded in units of maximum encoding units, based on information regarding the encoded depths and encoding modes of the maximum encoding units and the coding unit pattern information.

The image data decoder 1540 can check at least one encoded depth of the current maximum coding unit, and can detect hierarchical structures of encoding units according to the depths of a tree structure included in the current maximum coding unit, based on the information regarding the coded depths and coding modes of the maximum coding units.

Also, the image data decoder 1540 can decode the encoded image data by performing an inverse transformation into a transformation coefficient included in the texture information of the maximum coding unit extracted by the encoding unit pattern information extractor 1530 , based on the coding unit pattern information with respect to the maximum coding unit.

If the image data decoder 1540 corresponds to the image decoder 500 of Figure 5, then the transformation coefficient included in the texture information of encoding units can be reversed in time domain data using the inverse quantizer 530 and the inverse transformer 540. That is, if the encoding unit pattern information indicates that the texture information of the current encoding unit has been encoded according to the encoding unit pattern information, then the image data decoder 1540 may receive a Transformation coefficient that has been decoded by entropy from the decoder 520 by entropy of the image decoder 500 of Figure 5, and performing inverse transformation on the transformation coefficient to obtain spatial domain data. The spatial domain data can be reconstructed in a reconstructed frame using the intra predictor 550, the motion compensator 560, the unlocking unit 570, and the loop filtering unit 580 of the image decoder 500 of Figure 5.

The encoder unit pattern information extractor 1530 can detect at least one of coding pattern information of an encoded depth and hierarchical coding pattern information, such as coding unit pattern information with respect to coding units according to with coded depths for the current maximum coding unit.

If the encoding pattern information according to an encoded depth is detected, then the image data decoder 1540 can determine a decoding procedure of the encoding unit corresponding to the current encoded depth, based on the pattern information of encoding detected according to an encoded depth.

For example, if it is determined based on the encoding pattern information detected according to an encoded depth that texture information of the encoding unit corresponding to the current encoded depth has not been encoded, then the image data decoder 1540 You can decode the encoding unit that corresponds to the current encoded depth by referring to information regarding a data unit adjacent to the encoding unit that corresponds to the current encoded depth.

Also, if it is determined based on the encoding pattern information detected according to an encoded depth that the texture information of the encoding unit corresponding to the current encoded depth has been encoded, then the image data decoder 1540 may decode the coding unit corresponding to the current coded depth by performing inverse transformation into a transformation coefficient included in the coded texture information of the coding unit corresponding to the current coded depth.

Additionally, if the hierarchical coding pattern information is detected, the image data decoder 1540 can determine if hierarchical coding pattern information is present with respect to a lower transformation depth of a current transformation depth, and determine a procedure decoding of a transformation unit that corresponds to the current transformation depth based on the hierarchical coding unit pattern information detected.

For example, if it is determined based on the hierarchical coding unit pattern information detected that corresponds to the current transformation unit that corresponds to the transformation depth that the hierarchical coding pattern information with respect to the lower depth of the depth Current transformation is present, then the image data decoder 1540 can check the hierarchical coding pattern information with respect to the lower transformation depth. Without However, if it is determined based on the hierarchical coding unit pattern information that corresponds to the current transformation unit that the hierarchical coding pattern information with respect to the lower depth of the current transformation depth is not present, then The image data decoder 1540 can decode the current transformation unit corresponding to the current transformation depth.

If both the coding unit pattern information corresponding to an encoded depth and the hierarchical coding unit pattern information are detected, then the image data decoder 1540 can check if the hierarchical coding pattern information has been encoded with with respect to a lower transformation depth of the current transformation depth, based on the hierarchical coding unit pattern information with respect to the current transformation depth.

If it is determined that hierarchical coding pattern information is present with respect to the lower transformation depth, then the hierarchical coding pattern information with respect to the lower transformation depth can be checked. If it is determined based on the hierarchical coding unit pattern information corresponding to the current transformation depth that hierarchical coding pattern information is not present with respect to the lower transformation depth, then the image data decoder 1540 may decode the transformation unit corresponding to the current transformation depth, based on coding unit pattern information related to the transformation unit corresponding to the current transformation depth.

Also, if the current transformation depth is a lower depth or a final present depth, then the transformation unit corresponding to the current transformation depth can be set to be decoded independently of hierarchical coding pattern information according to depths. of transformation If the transformation unit corresponding to the current transformation depth is decoded, then the texture information can be decoded, for example, a quantification parameter, a transformation coefficient, a transformation index, etc.

The coding unit corresponding to the coded depth may include at least one transformation unit, and may be decoded by performing inverse transformation based on transformation unit pattern information that is established in each of the at least one transformation unit. That is, if the texture information of a desired transformation unit has been encoded it can be determined based on the transformation unit pattern information.

Therefore, if it is determined based on the encoding unit pattern information corresponding to the encoded depth that the encoding unit has encoded texture information, then the image data decoder 1540 checks transformation unit pattern information. of each of the transformation units of the coding unit.

If it is determined based on the transformation unit pattern information that the desired transformation unit has coded texture information, then the image data decoder 1540 can perform an inverse transformation on a transformation coefficient of the desired transformation unit. If it is determined based on the transformation unit pattern information that the desired transformation unit has no encoded texture information, then the image data decoder 1540 can decode encoded image data of the desired transformation unit using information regarding to a transformation unit adjacent to the desired transformation unit.

If it is determined based on the coding unit pattern information corresponding to the coded depth that the desired transformation unit does not have coded texture information, then transformation unit pattern information with respect to all units has not been encoded. of transformation of the desired coding unit. In this case, the image data decoder 1540 may not detect transformation unit pattern information for each of the transformation units of the desired coding unit.

In the video coding apparatus 1400 and the video decoding apparatus 1500 according to the disclosure, the encoding unit pattern information or transformation unit pattern information that has been encoded based on encoding units of the encoding units can be used. according to tree structures and transformation units. Therefore, it is possible to determine whether transformation unit pattern information of each of the transformation units has been encoded, based on coding unit pattern information that is set for an encoding unit having a plurality of groups of transformation units. Since the number of coding units is smaller than that of the transformation units, establishing coding unit pattern information for each of the coding units reduces the amount of data than when transforming unit pattern information is set. for each of all the transformation units, thereby improving the efficiency of bit transmission.

The coding unit pattern information that corresponds to a coded depth that is set according to color components of image data according to the disclosure it will now be described with reference to Figures 18 to 26. It is assumed in the following disclosures that a unit of coding unit pattern information is 1 bit, but You understand that you are not limited to the same.

Figures 18 to 20 are block diagrams illustrating coding unit pattern information corresponding to a coded depth when a coding unit corresponding to a coded depth includes a transformation unit.

Referring to Figures 18 to 20, a first image color data coding unit according to the YCbCr color standards includes a luminance component coding unit 1600, a first chrominance component coding unit 1610 , and a second chrominance component coding unit 1620 having a second chrominance component.

If a transformation unit of the first encoding unit is equal to the first encoding unit in size, then the first encoding unit includes only one transformation unit. Therefore, the transformation unit of the first coding unit includes a luminance component transformation unit 1605, a first chrominance component transformation unit 1615, and a second chrominance component transformation unit 1625. The transformation unit pattern information may be set for each of the luminance component transformation unit 1605, the first chrominance component transformation unit 1615, and the second chrominance component transformation unit 1625.

Referring to Figure 18, the coding unit pattern information corresponding to an encoded depth is not further coded for the first coding unit. In this case, the coding unit pattern information output unit 1450 of Figure 16 does not emit coding unit pattern information corresponding to a coded depth for the first coding unit. The image data decoder 1540 of Figure 17 can only check transformation unit pattern information for each of the luminance component transformation unit 1605, the first chrominance component transformation unit 1615, and the second unit 1625 of chrominance component transformation and performing an inverse transformation in transformation coefficients of the luminance component transformation unit 1605, the first chrominance component transformation unit 1615, and the second chrominance component transformation unit 1625, based on the test result, without checking coding unit pattern information corresponding to a coded depth for the first coding unit.

Referring to Figure 19, 1 bit coding unit pattern information is set corresponding to a coded depth for a group 1630 to which a luminance component transformation unit 1600 belongs, a first component transformation unit 1610 of chrominance, and a second unit 1620 of chrominance component transformation of a first coding unit. In this case, the coding unit pattern information output unit 1450 of Figure 16 issues the 1-bit coding unit pattern information corresponding to a coded depth for the first coding unit.

Referring to Figure 20, 1 bit coding unit pattern information is established corresponding to a coded depth for each of a group 1640 to which a luminance component coding unit 1600 of a first coding unit belongs. , and a group 1650 to which a first chrominance component coding unit 1610 and a second chrominance component coding unit 1620 of the first coding unit belong. In this case, the coding unit pattern information output unit 1450 of Figure 16 issues a 2-bit coding unit pattern information corresponding to a coded depth for the first coding unit.

The image data decoder 1540 of Figure 17 can determine if a desired coding unit includes coded texture information by checking any of the 1-bit coding unit pattern information corresponding to a coded depth of Figure 19 or the 2-bit coding unit pattern information corresponding to a coded depth of Figure 20, for a first coding unit. If the desired coding unit includes coded texture information, then the image data decoder 1540 of Figure 17 can check transformation unit pattern information of a corresponding transformation unit and perform inverse transformation on corresponding transformation coefficients, based in the test result.

Figures 21 to 23 illustrate coding unit pattern information corresponding to an encoded depth when an encoding unit corresponding to the encoded depth includes four transformation units. Referring to Figures 21 to 23, a second image color data coding unit according to the YCbCr color standards includes a 1700 luminance component coding unit, a first 1710 chrominance component coding unit , and a second 1720 chrominance component coding unit.

If the second coding unit includes four transformation units, then each of the coding units of the second coding unit, which are categorized according to a color component, also includes four transformation units. That is, the luminance component coding unit 1700 includes four luminance component transformation units 1702, 1704, 1706 and 1708, the first chrominance component coding unit 1710 includes first four units 1712, 1714, 1716 and 1718 of chrominance component transformation, and the second chrominance component coding unit 1720 includes four second units 1722, 1724, 1726 and 1728 of chrominance component transformation.

Referring to Figure 21, 1 bit coding unit pattern information is established corresponding to a coded depth for a group 1730 to which only the 1700 luminance component coding unit of the second coding unit belongs. However, no coding unit pattern information corresponding to a coding depth for the first chrominance component coding unit 1710 and the second chrominance component coding unit 1720 is established.

In this case, the coding unit pattern information output unit 1450 of Figure 16 issues 1-bit coding unit pattern information corresponding to the coded depth with respect to the 1700 luminance component coding unit . Accordingly, the image data decoder 1540 of Figure 17 checks the 1-bit coding unit pattern information that corresponds to the encoded depth with respect to the 1700 luminance component coding unit and determines if information is present. of texture coded in the 1700 luminance component coding unit. If it is determined that the encoded texture information is present, then the image data decoder 1540 can check transformation unit pattern information of the luminance component transformation units 1702, 1704, and perform reverse transformation in transformation coefficients of transformation units 1702, 1704, 1706 and 1708 based on the test result.

Alternatively, the image data decoder 1540 can only check transformation unit pattern information of the first chrominance component transformation units 1712, 1714, 1716 and 1718 and the second transformation units 1722, 1724, 1726 and 1728 of chrominance component and can perform an inverse transformation in transformation coefficients of the units 1712, 1714, 1716, 1718, 1722, 1724, 1726 and 1728 of transformation based on the test result, without checking coding unit pattern information which corresponds to an encoded depth of the first chrominance component 1710 and the second chrominance component 1720 of the second coding unit.

Referring to Figure 22, 1 bit coding unit pattern information is set corresponding to a coded depth for a group 1740 to which a 1700 luminance component coding unit belongs, a first 1710 component coding unit of chrominance, and a second chrominance component coding unit 1720 of a second coding unit. In this case, the coding unit pattern information output unit 1450 of Figure 16 issues the 1-bit coding unit pattern information corresponding to a coded depth for the second coding unit.

Referring to Figure 23, 1 bit coding unit pattern information is established corresponding to a coded depth for each of a group 1750 to which a 1700 luminance component coding unit of a second coding unit belongs. , a group 1760 to which a first chrominance component coding unit 1710 of the second coding unit belongs, and a group 1770 to which a second chrominance component coding unit 1720 of the second coding unit belongs. In this case, the coding unit pattern information output unit 1450 of Figure 16 issues a 3-bit coding unit pattern information corresponding to a coded depth for the second coding unit.

The image data decoder 1540 of Figure 17 can determine if coded texture information is present in an encoding unit by checking any of 1 bit encoding unit pattern information corresponding to the encoded depth (see Figure 22) or 3-bit coding unit pattern information corresponding to the coded depth (see Figure 23), for the second coding unit. If it is determined that the coded texture information is present, then the image data decoder 1540 can check transformation unit pattern information of transformation units corresponding to the coding unit and perform an inverse transformation into transformation coefficients of the transformation units based on the test result. Figures 24 to 26 illustrate coding unit pattern information corresponding to an encoded depth when an encoding unit corresponding to the encoded depth includes a plurality of transformation units. Referring to Figures 24 to 26, the third image color data coding unit according to YCbCr standards includes a 1800 component component coding unit. luminance, a first 1820 chrominance component coding unit, and a second 1830 chrominance component coding unit.

If the third coding unit includes at least four transformation units, then the luminance component coding unit 1800 of the third coding unit also includes at least four transformation units. That is, the number of transformation units of the luminance component coding unit 1800 is equal to the number of transformation units of the third coding unit. For example, if the third coding unit includes sixteen transformation units, then the luminance component coding unit 1800 also includes sixteen units 1801, 1802, 1803, 1804, 1805, 1806, 1807, 1808, 1809, 1810, 1811 , 1812, 1813, 1814, 1815 and 1816 of luminance component transformation.

Each of the first chrominance component coding unit 1820 and the second chrominance component coding unit 1830 may include four transformation units. That is, the first chrominance component coding unit 1810 may include first four chrominance component transformation units 1822, 1824, 1826 and 1828, and the second chrominance component coding units 1830 may include four second units 1832, 1834, 1836 and 1838 of chrominance component transformation.

An encoding unit pattern information unit corresponding to an encoded depth can be set as encoding unit pattern information corresponding to an encoded depth for a part of the luminance component coding unit 1800, for a group at that a predetermined number of luminance component transformation units belong. For example, coding unit pattern information corresponding to a coded depth for each of the groups to which four luminance component transformation units of the luminance component coding unit 1800 can be set. That is, in the luminance component coding unit 1800, 1-bit coding unit pattern information can be set for each of a group 1840 to which four transformation units 1801, 1802, 1803 and 1804 belong, a group 1850 to which four units 1805, 1806, 1807 and 1808 of transformation belong, an 1860 group to which four units 1809, 1810, 1811 and 1812 of transformation belong, and an 1870 group to which four units 1813, 1814, 1815 and 1816 belong of transformation

Referring to Figure 24, no coding unit pattern information corresponding to a coded depth for the first chrominance component coding unit 1820 and the second chrominance component coding unit 1830 is established.

In this case, the coding unit pattern information output unit 1450 of Figure 16 issues 4-bit coding pattern information corresponding to the coded depth for groups 1840, 1850, 1860 and 1870 of unit 1800 of luminance component coding. The image data decoder 1540 of Figure 17 checks the 4-bit coding pattern information that corresponds to the encoded depth, and determines whether coded texture information is present for each of the groups 1840, 1850, 1860 and 1870 .

Alternatively, the image data decoder 1540 can check transformation unit pattern information of the first chrominance component transformation units 1822, 1824, 1826 and 1828 and the second 1832, 1834, 1836 and 1838 transformation units. Chrominance component without checking pattern information corresponding to the coded depth for the first chrominance component 1820 and the second chrominance component coding unit 1830.

Referring to Figure 25, in a third coding unit, 1 bit coding unit pattern information is established corresponding to a coded depth for each of a plurality of groups 1840, 1850, 1860 and 1870 units of luminance component coding, a group 1880 to which a first chrominance component coding unit 1820 belongs, and a group 1885 to which a second chrominance component coding unit 1830 belongs. In this case, the coding unit pattern information output unit 1450 of Figure 16 issues 6-bit coding unit pattern information corresponding to the encoded depth, for the third coding unit.

Referring to Figure 26, in a third coding unit, 1-bit coding unit pattern information is established corresponding to a coded depth for each of a plurality of groups 1840, 1850, 1860 and 1870 units of luminance component coding, and a group 1890 to which a first chrominance component coding unit 1820 and a second chrominance component coding unit 1830 belong. In this case, the coding unit pattern information output unit 1450 of Figure 16 issues 5-bit coding unit pattern information corresponding to the encoded depth, for the third coding unit.

The image data decoder 1540 of Figure 17 determines whether coded texture information is present for the coding unit by checking any of the unit pattern pattern information. 6-bit coding corresponding to the coded depth (see Figure 25) or the 5-bit coding unit pattern information corresponding to the coded depth (see Figure 26) for the third coding unit. If it is determined that the coded texture information is present, the image data decoder 1540 can check transformation unit pattern information of a transformation unit included in the coding unit, and perform an inverse transformation into transformation coefficients of the transformation units based on the test result.

As described above, according to one or more exemplary embodiments, coding unit pattern information can be established for each of the color components, and a plurality of pieces of coding unit pattern information of the same unit Encoding, which are categorized according to a color component, can be combined and encoded.

In a video coding apparatus 100 and a video decoding apparatus 200 according to the disclosure a plurality of pieces of coding unit pattern information that are categorized according to a color component can be encoded or decoded in a manner integrated, based on the relationship between coding unit pattern information with respect to a luminance component, first chrominance component, and second chrominance component of the same coding unit and the relationship between coding unit pattern information of the same color component with respect to neighboring coding units.

For example, for variable length coding (VLC) of a current coding unit, coding unit pattern information with respect to a luminance component, coding unit pattern information with respect to a first component can be combined and encoded of chrominance, and coding unit pattern information with respect to a second chrominance component using a code word.

Additionally, by way of example, a VLC table can be established such that different unary code words correspond to combinations of a plurality of pieces of coding unit pattern information, which are categorized according to a color component, respectively. Accordingly, the plurality of pieces of coding unit pattern information can be encoded in an integrated manner. A VLC table can be selected in such a way that the shorter the unary code word is, the higher the probabilities of combinations of the plurality of pieces of coding unit pattern information.

As described above, it is possible to improve the coding efficiency by encoding or decoding a plurality of pieces of coding unit pattern information, which are categorized according to a color component, in an integrated manner, based on the relationship between a plurality of pieces of coding unit pattern information of the same coding unit that are categorized according to a color component and the relationship between a plurality of pieces of coding unit pattern information of the same color component of neighboring coding units.

According to the disclosure, coding unit pattern information corresponding to a coded depth in a coding unit corresponding to the coded depth is established, hierarchical coding unit pattern information is established in transformation units according to transformation depths, which are divided from the coding unit that corresponds to the encoded depth, and transformation unit pattern information is established in a final transformation unit. Therefore, the coding unit pattern information corresponding to the encoded depth, the hierarchical coding unit pattern information, and the transformation unit pattern information can be defined continuously, based on the hierarchical structures of a coding unit and a transformation unit according to an exemplary embodiment.

Accordingly, in the video coding apparatus 100 and the video decoding apparatus 200 according to the disclosure it is possible to determine whether a texture component that is not 0 and that is included from an encoding unit to a transformation unit it has been encoded using a piece of data unit pattern information that is set hierarchically according to a transformation depth, without differentiating from each other the coding unit pattern information corresponding to the encoded depth, the information of hierarchical coding unit pattern, and transformation unit pattern information.

Figure 27 is a diagram illustrating hierarchical coding unit pattern information in accordance with the disclosure. Referring to Figure 27, the units 1912, 1914, 1916, 1918, 1920, 1930, 1942, 1944, 1946, 1948, 1954, 1956 and 1958 are established, the sizes of which are determined according to depths of corresponding transformation, respectively, for a 1900 unit of maximum coding. For example, a transformation unit that corresponds to the transformation depth of 0 is equal to the maximum size coding unit 1900, although the maximum coding unit 1900 illustrated in Figure 27 does not include the transformation unit corresponding to the transformation depth of 0.

The transformation units 1920 and 1930 are equal to the result of dividing the height and width of the transformation unit into two equal parts corresponding to the transformation depth of 0, and correspond to a transformation depth of 1. Similarly, the 1912, 1914, 1916, 1918, 1954, 1956 and 1958 transformation units correspond to a transformation depth of 2, and the 1942, 1944, 1946 and 1948 transformation units correspond to a transformation depth of 3.

The hierarchical coding unit pattern information indicates whether hierarchical coding unit pattern information is to be encoded with respect to a lower transformation depth. Additionally, the hierarchical coding unit pattern information may reveal whether texture information of the lower transformation depth has been encoded.

The maximum coding unit 1900 does not include the transformation unit that corresponds to the transformation depth of 0, and uses texture information of a transformation unit that corresponds to the transformation depth of 1 that is less than the transformation depth of 0. Therefore, 1960 hierarchical 1-bit coding unit pattern information is set for the transformation depth of 0.

With respect to the transformation depth of 1, the transformation units 1920 and 1930 are decoded at the transformation depth of 1, and therefore, texture information of a transformation unit corresponding to the depth transformation may not be encoded. 2 which is less than the transformation depth of 1. Also, hierarchical coding unit pattern information with respect to the transformation depth of 2 may not be established. Therefore, coding unit pattern pattern information may not be encoded. 1 hierarchical bit with respect to the transformation depth of 1, which indicates that hierarchical coding unit pattern information texture information is provided with respect to the transformation depth of 2, for each of the 1920 and 1930 units of transformation.

However, texture information of a transformation unit that corresponds to the transformation depth of 2 that is less than the transformation depth of 1 for each of a group, which corresponds to the transformation depth of 1, must be encoded , to which belong the units 1912, 1914, 1916, and 1918 of transformation that correspond to the depth of transformation of 2, and a group, which corresponds to the depth of transformation of 1, to which the units 1942, 1944, 1946 belong , 1948, 1954 and 1956 and 1958 of transformation. Therefore, coding unit pattern information with respect to the transformation depth of 2 can be encoded, and hierarchical 1 bit coding unit pattern information with respect to the transformation depth of 1 can be set for each of the groups to indicate this fact.

Accordingly, a total of 1970 4-bit hierarchical coding unit pattern information is set for the transformation depth of 1.

With respect to the transformation depth of 2, the 1912, 1914, 1916, 1918, 1954, 1956 and 1958 transformation units may be decoded at the transformation depth of 2. For this reason, texture information of a unit may not be encoded. of transformation corresponding to the transformation depth of 3 that is less than the transformation depth of 2, and therefore, hierarchical coding unit pattern information with respect to the transformation depth of 3. may not be established. therefore, hierarchical 1-bit coding unit pattern information can be set with respect to the transformation depth of 2 for each of the transformation units 1912, 1914, 1916, 1918, 1954, 1956 and 1958 to indicate that it cannot coding information of hierarchical coding unit pattern with respect to the transformation depth of 3.

However, information about a transformation unit corresponding to the transformation depth of 3 for a group, corresponding to the transformation depth of 2, to which the transformation units 1942, 1944, 1946 and 1948 belong can be encoded. Therefore, the coding unit pattern information with respect to the transformation depth of 3 can be encoded, and a hierarchical 1 bit coding unit pattern information with respect to the transformation depth of 2 can be set to indicate this done.

Accordingly, a total of 8-bit hierarchical coding unit pattern information 1980 for the transformation depth of 2 can be established.

The transformation depth of 3 is a final transformation depth, and therefore, hierarchical 1-bit coding unit pattern information can be set with respect to the transformation depth of 3 for each of the units 1942, 1944, 1946 and 1948 transformation to indicate that hierarchical coding unit pattern information cannot be encoded with respect to a lower transformation depth. Therefore, a total of 1990 4-bit hierarchical coding unit pattern information for the transformation depth of 3 can be established,

Figure 28 is a flow chart illustrating a method of encoding video data using coding unit pattern information, in accordance with the disclosure. Referring to Figure 28, In operation 2010, a current snapshot is divided into at least one unit of maximum coding. In operation 2020, a coded depth is determined to emit a final coding result according to at least one division region, which is obtained by dividing a region of each of the at least one maximum coding unit according to the depths , by encoding the at least one division region, and a coding unit is determined according to a tree structure.

In operation 2030, an image data encoding result is output according to an encoded depth for each of the at least one maximum encoding unit, and an information encoding result with respect to the encoded depth and a mode of coding.

The encoding unit pattern information corresponding to an encoded depth, which indicates whether texture information of encoding units has been encoded according to encoded depths of the at least one maximum coding unit, can be encoded as pattern information of coding unit of the at least one maximum coding unit. If hierarchical coding unit pattern information is coded hierarchically according to a transformation depth, then each of a plurality of pieces of hierarchical coding unit pattern information corresponding to transformation depths indicates whether the information has been coded. of hierarchical coding unit pattern with respect to a transformation depth that is less than the corresponding transformation depth.

Figure 29 is a flowchart illustrating a method of decoding video data using coding unit pattern information, in accordance with an exemplary embodiment. Referring to Figure 29, in step 2110, a sequence of encoded video bits is received and analyzed.

In step 2120, the image data of a current snapshot assigned to at least one maximum encoding unit, information is extracted with respect to an encoded depth of an encoding unit according to a tree structure for each of the minus a maximum coding unit, and information regarding an encoding mode, from the bit sequence analyzed. Also, the coding unit pattern information is extracted which indicates whether texture information of a maximum coding unit has been encoded based on the at least one maximum coding unit. Coding unit pattern information corresponding to a coded depth with respect to coding units according to encoded depths of each maximum coding unit, and hierarchical coding unit pattern information such as coding unit pattern information can be extracted of the at least one unit of maximum coding.

In step 2130, encoded image data corresponding to the at least one maximum encoding unit is decoded, based on the encoded depths of the at least one maximum encoding unit, information regarding an encoding mode, and information with regarding the coding unit pattern information, thereby reconstructing the image data. It is possible to determine whether texture information of the coding unit corresponding to the encoded depth has been encoded based on the encoding unit pattern information corresponding to the encoded depth. Also, it is possible to determine whether the hierarchical coding unit pattern information has been encoded with respect to a lower transformation depth based on the hierarchical coding unit pattern information with respect to each of the transformation depths.

In the coding unit corresponding to the encoded depth, data encoded in a transformation unit can be decoded by performing an inverse transformation in a transformation coefficient based on transformation unit pattern information of the transformation unit.

In general, in a video coding / decoding procedure of the related art, a 16x16 or 8x8 macroblock is used as a transformation unit when reverse transformation or transformation is performed on image data. The encoded block pattern information is encoded and transmitted on a macro block basis during an encoding procedure and is used for a decoding procedure.

In contrast, according to the exemplary embodiment described above, coding unit pattern information based on a hierarchically structured coding unit and transformation unit is used. Therefore, the encoding unit pattern information can be encoded in an encoding unit that is larger than a macroblock or has a variable size data unit. Also, the coding unit pattern information can be encoded in an encoding unit, which includes a plurality of hierarchically structured transformation units according to a tree structure, in an integrated manner. Accordingly, the encoding / decoding efficiency and transmission of the coding unit pattern information can be improved.

One or more exemplary embodiments may be performed as a computer program. The computer program can be stored in a computer readable recording medium, and is executed using a general digital computer. Examples of the computer-readable medium include a magnetic recording medium (a ROM, a flexible disk, a hard disk, etc.), and an optical recording medium (a CD-ROM, a DVD, etc.).

Claims (3)

1. A video decoding procedure, the procedure comprising: extract, from a sequence of bits, encoded image data of a current snapshot assigned to a maximum encoding unit of the current snapshot; extracting, from the sequence of bits, information about a coded depth for the maximum coding unit in which the information about the coded depth comprises division information of a current coding unit, the maximum coding unit is hierarchically divided into coding units of at least one depth according to the division information which is a flag indicating whether the current coding unit of a current depth, between the coding units, is divided into coding units of a lower depth; when the division information of the current coding unit indicates that the current coding unit of the current depth is no longer divided as the current coding unit of the encoded depth, extracting, from the sequence of bits, information about a mode of prediction of the current coding unit indicating an intra mode or an inter mode, information about a type of partition indicating a size of a prediction unit included in the current coding unit and information about a size of a unit of transforming the current coding unit, determining at least one prediction unit obtained from the current coding unit using information about a type of partition and determining at least one transformation unit obtained from the current coding unit using the information about a size of a transformation unit; perform intra prediction or inter prediction in the current coding unit based on the at least one prediction unit using information about a prediction mode; extract, from the sequence of bits, coding unit pattern information indicating whether texture information of the current coding unit has been encoded; according to whether the coding unit pattern information indicates that the texture information of the current coding unit has been encoded, extracting, from the bit sequence, transformation unit pattern information indicating whether information has been encoded of texture of a transformation unit of the at least one transformation unit; according to whether the transformation unit pattern information indicates that the texture information of the transformation unit has been encoded, perform an inverse transformation in the transformation unit; and decode the encoded image data for the maximum coding unit based on the prediction unit and the transformation unit included in the current coding unit, in which the maximum coding unit has a square shape with a width and height in powers of 2, wherein the transformation unit pattern information of a luminance component transformation unit indicates whether texture information of the luminance component transformation unit has been encoded; Y wherein the transformation unit pattern information of a chromatic component transformation unit indicates whether texture information of the chromatic component transformation unit has been encoded. 2. The method of claim 1; wherein the size of the luminance component transformation unit and the chromatic component transformation unit is less than or equal to the size of the coding unit. 3. The video decoding method of claim 2, wherein the luminance component transformation unit and the chromatic component transformation unit are obtained by halving the height and width of the coding unit.